An experimental Italian AIDS vaccine will soon be tested on humans. Virologist Barbara Ensoli and her team have been developing the vaccine at the Rome-based Italian Health Institute (ISS) since 1996. After testing the drug with positive results on animals, it will now be tried out on 88 volunteers (32 of them healthy and 56 HIV positive) aged between 18 and 50 in clinics in Rome and in Milan. The first phase of the tests will last 12 months and aims to discover if the vaccine is innocuous. Should this be the case, testing to discover if it can protect against the virus and reduce the disease's progression will begin; definitive results are not expected for at least six years. The vaccine works by blocking the actions of a protein called Tat, which helps the virus replicate at very early stages. In Italy 110,000 people are HIV positive, and 52,000 have developed AIDS since 1982. More than three million people died from AIDS worldwide in 2003.